The present invention relates to an electrical connector for electrically interconnecting two boards or equivalent.
In recent years, with increase in the number of input and output lines, such as signal lines and electric power lines, to the boards built in electrical equipment such as computers, multicore electrical connectors are often used as a board-to-board electrical connector for interconnecting the two boards. In addition, since fast signals may be included in the input and output to and from the boards, some of the electrical connectors take measurements against noises through the use of the transmission line structure formed by the signal lines and the ground planes.
In the electrical connector having a pair of male and female connectors for instance, the pair of male and female connectors are each provided with terminals having contacts for signal line and for conductor plates for ground plane. When the terminals of one connector and the related terminals of the other connector are fitted to each other, the contacts of the terminals of the respective connectors are brought into contact with each other to form the signal lines and also the conductor plates are brought into contact with each other to form the ground planes.
However, this conventional type of electrical connector has a disadvantage that the distances between the signal lines and the ground planes undergo drastic changes in the region where the respective contacts are brought into contact with each other and the respective conductor plates are brought into contact with each other. If the distances between the signal lines and the ground planes in the transmission lines undergo drastic changes, then the impedances of the transmission lines will not be kept stable, i.e., the impedance characteristics will be varied by the frequencies. If the impedances of the transmission lines are not kept stable, then there will arise the problem that even when the electrical connector is designed to produce a desired impedance at a certain frequency, the electrical connector thus designed will not produce the desired impedance at different frequencies from the certain frequency and, as a result, losses will increase at the different frequencies.
It is the object of the present invention to provide an electrical connector that can provide stabilized impedances of transmission lines in the electrical connector.
An electrical connector of the present invention comprises a first connector having a first contact; and a second connector having a second contact which is brought into contact with the first contact when the second connector is fitted to the first connector, wherein a conductor plate, which extends in a substantially parallel relation to the first contact and the second contact when the first connector and the second connector are fitted to each other, is provided in at lease either of the first connector and the second connector; and wherein an end portion of the first contact and an end portion of the second contact, which are to be contacted with each other, are so shaped that the distance between the contact portions of the first and second contacts and the conductor plate can be made substantially equal to the distance between portions of the first and second contacts except their contact portions and the conductor plate.
According to the electrical connector thus constructed, since the end portion of the first contact and the end portion of the second contact which are to be contacted with each other are so shaped that the distance between the contact portions of the first and second contacts and the conductor plate can be made substantially equal to the distance between portions of the first and second contacts except their contact portions and the conductor plate, the distance between the signal line formed by the first and second contacts being contacted with each other when the first connector and the second connector are fitted to each other and the conductor plate (the ground plane) can be kept substantially uniform. As a result of this, the impedance of the transmission line can be stabilized.
In the electrical connector mentioned above, the first connector is provided with two first contacts which are put in a parallel relation with each other and spaced at a substantially equal distance to the conductor plate when the first connector and the second connector are fitted to each other, and wherein the second connector is provided with two second contacts which are put in a parallel relation with each other and spaced at a substantially equal distance to the conductor plate when the first connector and the second connector are fitted to each other.
According to the electrical connector thus constructed, since the two signal lines are formed which are put in a parallel relation with the ground plane (the conductor plate) and spaced at a substantially equal distance to the ground plane, transmission of differential signals can be provided.
In the electrical connector mentioned above, a plurality of conductor plates provided in at least either of the first connector and the second connector are spaced in a confronting relation to each other; the first connector is provided with one or more first contacts which are placed between each pair of conductor plates when the first connector and the second connector are fitted to each other; and the second connector is provided with one or more second contacts which are placed between each pair of conductor plates when the first connector and the second connector are fitted to each other.
According to the electrical connector thus constructed, since the conductor plate is placed between each pair of the signal lines formed by the first and second contacts being contacted with each other, the signals transmitted through the respective signal lines can be prevented from interfering with each other.